The loudness war in the strict "we must compress and slam everything as much as possible to make our stuff sound good on the radio" sense is over thanks to Spotify et al doing loudness normalization, but there's still an open question of "how much compression does sound good?" which is extremely subjective. A lot of modern music is louder than peak loudness war stuff just because the creators want their music to be slammed to shit. I listen to/make aggressive bass music and -5, -4, -3 LUFS are common. (By comparison, some of the common examples of loudness war era CDs like Definitely Maybe and Californication sit between -8 and -6 LUFS.)

> Especially since the answer to any loudness problem is to simply for the user to turn up the volume.

This isn't quite true as compression addresses differences in volume. Unless you expect the listener to actively turn up the volume during the quiet parts and down during the loud parts of your song, or be listening in a completely quiet environment with nothing but the music so they can appreciate the dynamics--which is the way a lot of vinyl aficionados do listen to music.